It's unclear whether that's a recent change or a long-standing issue,
however currently if geocode is called with an empty address string it
will reply with a 400 Bad Request, which gets raised as an exception and
forwarded to the user. That is not a great experience.
Shortcut the entire thing and just return None (= geolocation failed /
no geolocation) on trying to geolocate an empty address.
OPW-746686
backport of 74a89bcf5c
xmo-odoo
c50745f1a1